What a Flame Sensor Is and Why It Matters

Setting up your annual furnace maintenance helps keep your furnace operating up to 30% more efficient and helps extend the life of your system. But things may still go wrong, and when they do, you may feel like you’re always hearing about something else. 

This time it’s your blower, next time it’s your pressure switch. Now you need to replace your flame sensor. 

Also, what is a flame sensor? 

A flame sensor is a crucial safety feature on your gas heating system. During the ignition pattern, your gas furnace goes through a process where either a hot surface ignitor or a spark actually ignites the gas. When the gas is ignited, the flame sensor generates a current of electricity. The electricity is quantified in micro amps. If the furnace’s control board doesn’t read the right level of micro amps, the furnace will quit giving the system fuel to stop an explosion. 

Over time, if the flame sensor is not cleaned appropriately, oxidation or carbon buildup can restrict the flame sensor’s ability to operate properly, which can cause the furnace to malfunction. 

The way to determine if a soiled flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert heating technician can supply you. If a dirty flame sensor is the guilty party, the furnace expert will clean the sensor with steel wool. If dirt was the sole factor, we will see a significantly higher amp reading. If the reading shows no change, the technician will carry on with the heating equipment repair diagnostic process. 

If you aren’t sure your furnace is going to make it through these last few weeks of winter, give Stallion Heating and Air Conditioning a call and we’ll come out and provide you with a full furnace maintenance or a free in-home estimate on a new heating system.